1. Field of the Invention
The present invention relates to an optical device, and more particularly, to a silicon array waveguide grating (AWG) device.
2. Description of the Related Art
Array waveguide grating (AWG) devices are conventionally formed of silica, but since semiconductor chips are formed of silicon, there is a demand for silicon AWG devices, formed of silicon.
Silicon AWG devices require optical wiring for high speed silicon based semiconductor devices such as CPUs. In other words, silicon AWG devices require optical wiring between semiconductor chips based on silicon.
However, the variation of refractive index of a silicon material is 0.00018/° C., which is 18 times that of a silica material, which is 0.00001/° C. Therefore the optical waveguide of a silicon AWG device has an extreme variation of its effective refractive index according to temperature compared to a silica AWG device. This causes a variation of the center wavelength according to temperature as great as 0.18 nm/° C., and it becomes difficult to use the silicon AWG device.